As the complexity of computer systems has increased, the operating system executing in the computer systems have also become more sophisticated. Specifically, operating systems have been augmented to include resource management utilities. Resource management utilities enable system users to control how processes executing on the computer system use the available system resources (e.g., central processing units (CPUs), physical memory, bandwidth, etc.).
The resource management utilities provide a number of different resource management control mechanisms to control system resource allocation for processes, such as CPU shares allocation, physical memory control, system resource partitioning, etc. Each of the aforementioned resource management control mechanisms may be applied independently and individually to each application (or service (i.e., group of related applications) executing on the computer system. Alternatively, each of the aforementioned resource management control mechanisms may be applied to one or more applications in combination. The resource management control mechanisms described above may be generically categorized into three distinct types: constraint mechanisms, scheduling mechanisms, and partitioning mechanisms.
Constraint mechanisms allow a system user (e.g., a system administrator) or an application developer to set bounds on the consumption of a specific system resource for an application or one or more processes within an application. Once the bounds on resource consumption are specified, the system user and/or application developer may readily and easily model system resource consumption scenarios. Further, the bounds on resource consumption may also be used to control ill-behaved applications that would otherwise compromise computer system performance or availability through unregulated system resource requests.
Scheduling mechanisms allow a system to make a sequence of system resource allocation decisions at specific time intervals. The decision about how to allocate a particular system resource is typically based on a predictable algorithm. In some instances, the scheduling algorithm might guarantee that all applications have some access to the system resource. Scheduling mechanisms enable improved utilization of an under committed system resource, while providing controlled allocations in a critically committed or overcommitted system resource utilization scenario.
Partitioning mechanisms allow a system user to bind a particular application (or one or more sub-processes within the application) to a subset of available system resources. This binding guarantees that a known amount of system resources is always available to the application (or one or more sub-processes within the application).
Operating systems providing the above-mentioned resource management control mechanisms typically provide a resource management utility and/or an application programming interface (API) for each of the mechanisms. Further, each of the resource management utilities/APIs provides a number of different options for the system user to select and configure. In general, the resource management utilities/APIs are not tightly coupled together. In addition, as the operating system evolves, different versions of the resource management utilities/APIs become available that have different options and functionality. Accordingly, in order for a system user to take advantage of the aforementioned mechanisms, the system user typically requires a thorough understanding of the different types of resource management control mechanisms as well as the relationship/interaction between the various resource management control mechanisms.